Asbestos-aluminum powder paint



Patented June 3, 1952 ASBESTOS-ALUMINUM POWDER PAINT Frederick A. Stolz, San Francisco, andEdley J.

Vaught, J r.,

Oakland, Calif.,

assignors to Pabco Products Inc., a corporation of Delaware No Drawing. Application July 22, 1950,

Serial No. 175,468

6 Claims. (01. 260-2815):

v This invention relates to a metallic bituminous paint, "and more particularly to such paint containing flaked aluminum powder which imparts to the dry paint coating or film an ornamental metallic appearance, and which also contains a filler the majority of which is asbestos fiber to 'enable the paint to be'applied as a single relatively'thick coat compared to such paint without the filler, I

A- paint-of this character is disclosed in assignees patent to Buchanan, No. 2,477,236, dated July 26, 1949,-in which the binder for the paint is entirely of bituminous material, and the paint issolvent-thinned so that itsviscosity is such as to enable it to be applied to a surface by brushing or'spraying. Q 1 j V 1 Summarizing thisrinvention, the paint thereof is an improvement over the paint disclosed in the-patent, by increase of the solvent content of the'paint with respect to the quantity of binder in the;paint, so that the aluminum powder or flakes will have enhanced floating power to the surface of the paint when applied and thus provide an improved metallic color and retention of such color at the surface, and also increase of the filler content of thepaint compared to the quantity of the binder to improve the matting qualities of the'paint. I In addition, instead of a binder which is entirely of bituminous material as is disclosedlin the patent, the binder of this invention is a mixture of bituminous material and a relatively light colored resin derived from'coal tar (hereinafter referred to as coal tar derivative resin), preferably a coumarone-indene resin well known in the varnish making art. Such resin is compatible with the bituminous material of the binder. The invention has as its objects, among others, the provision of an improvedpaint of the character related, having enhanced fioatability of the aluminum powder and an improved binder in the paint, which is economical and easy to apply by brushing or by spraying, and which can be readily manufactured. I, v

The improved binder of the paint is an important feature of theinvention because if the binder is entirely of bituminous material, such as asphalt, as disclosed in the aforementioned patent, it sometimes turns brown after exposure'to the elements for a substantial period of time and discolors the aluminum flakes or powder which may have worked up to the surface of the paint. Incorporation of the light colored coal tar derivative resin in the bituminous material of the binder obviates this problem and 2 1' r "preserves the brilliancy of the metallic film. 'In this connection, petroleum derivative resins are notsatisfactory for thispurpose. Although any suitable relatively light colored coal tar derivative resin common in the varnish making art may be utilized, coumarone-indene resins employed in the varnish making art, are most satisiactory, and the coumarone-indene resin known in the trade as EX cumar is preferred; This resin has a melting point in the range of 100 C. to 115 C., and is substantially non-acid, having a substantially neutral reaction.

About equal proportions by weight of the resin and the bituminous material provide the 'most satisfactory binder and are preferred. 'If too much resin is employed, cracking or so-called alligatoring of the dried binder film may result. Too little of the resin will not overcome the discoloration effect previously mentioned. About the maximum amount of resin that should be utilized is parts by weight to about 25 parts by weight of the bituminous material. The minimum amount is about 25 parts by Weight of the resin to about 75 parts by weight of the bitumi- The bituminous material is required in the binder in order to render the paint compatible with the usual bituminous coating on felt base roofing material for which the paint is particularly adapted as a-coating therefor.

'The paint consists essentiallyof the described binder,- volatile solvent for the binder, filler which is preferably all asbestos fiber, but if not, the majority of which is asbestos fiber, and the flaked aluminumpowder. In other words, Substantially all or of the paint is composed of these four materials. The volatile solvent is the major constituent in that the quantity by weight is in excess of any other substance of the paint, and is in such excess with respect to the weight of the aluminum powder and the weight of .the binderas to cause the powder to fioattothe surface of the fresh paint without being covered by a substantial film of the binder.

According to the improved range of proportions of the instant formulation, the total quan tity of binder and the solvent constitutes from about 67% to about 82% by weight of the total weight of the paint, and the total quantity of the filler and the aluminum powder about 18% to about 33% of the total weight of the paint.

Although the ratio of the aluminum powder to.

the filler is not so critical to obtain the improved metallic appearance of the paint, the solvent to binder ratio should be from about 3 to 6 parts by weight of the solvent to about 1 part by weight The amount by weight of the of the binder. filler to the aluminum powder may vary from about 0.8 to 2.5 parts by weight'of the filler to about 1 part by weight of the powder.

Preferably, the amount by weight of the alu minum powder to the'binder should be some-. what less than that of. the binder but may vary from about 1 to about 2 parts by weight-of the binder to about 1 part by weight of the aluminum powder. The amount by weight of the filler to the binder may vary from about 0.55 to 1.7 parts by weight of the binder to about 1 part by weight of the filler, but it is desirable that the filler be in excess with respect to the binder for best matting efiect.

The following formula expresses the preferred range: of proportion in approximate parts an percent byweight.

The preferred commercial formulation will be described hereinafter. V

As is described in the aforementionad patent, instead of substantially pure aluminum powder, any of the wellknown commercial aluminum pastes suitable for blending with varnish, or other vehicle for making bronzing paintsmay be employed instead. Such aluminum pastev contains volatile solvent; and when employed, the quantity of volatile solvent otherwise used in a specific paint formula should be reduced a proportionate amount. Aluminum paste contains approximately 30 to 35 percent by weight of volatile solvent; so that with the powder, approximately 30 to 35 percent less by weight is used in the paint compared to the quantity of aluminum paste, and the difference made up by additional solvent.

With respect to the preceding formula range,

of the resultant paint coating. This determines the coarseness of the fiber from a practical purpose.

A fiber having'a grading of 0-4-8-4 on the same basis mentioned will produce a 1 usable product. but in-addition to; a rougher fil m, the paint itself will not have as good. a spreading capacity as the paint with finer fiber. Finer fiber, as low as 0-01-15 grading or evenllower,

may be employed but then the paint maynot result in as thick a film as desired. In place of the preferred Canadian asbestos fiber, other sources of asbestos may be employed, such as Arizona or Vermont'asbestos, which lend themselves readily to breaking up into the preferred mesh size and which may be readily dispersed in the'paint.

Some of the fiber may be replaced by'suitable extenders, such as comminuted diatomaceous earth, powdered talc or soapstone. If diatomaceous earth is employed, about .20 %.to of the volume of. asbestos fiber maybe replaced'by the 'earth. Powdered talc or soapstone may be substituted pound for pound for an equal weight of the asbestos fiber, up to about 20% of the total weight of fiber. Finely ground anthophyllite or tremollite'may be usedunder similar conditions. It is important for best results that a substantial proportion or majority of the filler tile solvent.

and subsequent particular formulae, only aluminum powder appears. Consequently, it is to be understoodfthat the proportions of the aluminum and the solvent may be varied along the lines discussed according to whether the aluminumpaste is substituted for the aluminum pow- 1- der, or vice versa. The same is to be understood with respect to claims that recite proportions.

As the filler, asbestos type fiber is the most suitable; and it is preferred for best results.

Preferably, the fiber is so-called Canadian asbestos fiber of 0-0-10-6 commercial grade, namely the number of ounces of fiber in a 16 I ounce sample that are retained on successive screens of in., A; in., and in. mesh and that pass throughthe in. mesh, respectively. The

coarser the fiber the rougher will be the surface be of the asbestos type fiber, although some of the asbestos type fiber may be replaced in part by suitable extenders. V I

. In addition to extenders of the type described above, color effects may be obtained .in the paint, by employment of suitable relativelysmall proportions of color pigments to replace some of the fiber, or extenders" if T employed, without loss of the metallic appearing surfaceproduced by the aluminum ipo wder. For example, iron oxide may be used to produce a pleasingreddish color almost like metallic copper. Graphite may be used to produce a metallic slate appearance, and chrome oxide will impart agreenish tinge to the metallic lustre created bythe aluminum. These pigments are employable in; conjunction with the essential ingredients of our paint, namely, the filler,prefer'ably asbestos-type fiber, the binder, the aluminum powder, and thefvola- I Asphaltis the preferred bituminousmaterial in the binder; and although asphalt of the spe cific type disclosed in the aformentioned Patent may :be employed, it is desirable because of the presence of the resin in the-binder, to employ as.-

phalt having a somewhat lower softening point,

namely, an asphalt having an A. S. T. M. (Ball and. Ring method) softening point in the range of F. to F.', and an A. S, T M. penetra tion at 77F. in therang e of 51 to 60. I

Coal tar pitches having characteristicssimilar to the preferred asphalt may be used as the. bituminous material in the binder. However, stearine pitches, although they may be -employed, do not produce as good results as the asphalt, or coal tar pitches V I I For enhancement of superior floating, effectin bringing the aluminum powder to the surface,,the volatile solvent should have a high aromatic'content such as the crude coaltar naptha solvent disclosed in the aforementioned patent. The floating effect makes for increased brilliancy obtainable bythe aluminum powder. .Coaltar solvents have the desiredhigh aromatic content, and'other coal tar solvents such asitoluoland xylol may be employed. The solvent may be entirely of the coal tar type described but because of the presence of the resin in the binder, it lends itself to dilution very readily with the much less costly mineral spirit type of solvents which are well known straight chain olefine hydrocarbons derived from petroleum.

If straight mineral spirits were employed alone as the solvent, the desirable floating effect could not be obtained. Consequently, for obtaining such floating effect, the solvent should have at least by weight of the high aromatic content solvent mentioned, and preferably not lessthan 120% by weight of such high aromatic content solvent. As previously mentioned, the solvent may be entirely of the high content aromatic type, such as the coal tar solvents, but it is desired to dilute the same in the manner related for purposes of economy.

The preferred coal tar naptha solvent is the same as that described in the patent, having aspecific gravity at 155 C. in the range of about 0.85 to 0.91, and a distillation temperature in the range of 150 C. to 200 C. The preferred min.- eral spirit solvent diluent has a specific gravity at 25 F. in the range of 0.79 to 0.82 and a distillation temperature in the range of between 305 F. to 410 F.

The following are typical formulae of the paint of this invention, the formula of Example I being commercially preferred:

Example I Parts and Parts and Percent Percent by Weight by Weight Binder 14 Asphalt (A. S. T. M. (Ball and Ring) softening point 110F. to 120F. and penetration at 77F. of 51 to 60) 7 Coumarone-Indene Resin (EX Cumar") (Melting point 100C. to 115C.) 7

Total l4 Volatile Solvent for Binder 56 Crude coal tar naphtha solvent (Specific gravity at 15.5O., 0.85 to 0.91) (Distillation range 150C. to 200C.). 13 Mineral Spirits (Specific gravity at 25F., 0.79 to 0.82) (Distillation range 305F. to 410F.) 43

Total 56 Aluminum Powder (Alcoa A-322) 10 Asbestos Fiber (0-0-10-6 mesh on basis described above) l 20 Example II Parts and Parts and Percent Percent by Weight by Weight Binder l5 Asphalt (same as in Exam le 1) 9 Ooumarone-Indene Resin Same as in Example I) 6 Total l5 Volatile Solvent for Binder 56 Crude Coal tar naphtha Solvent (Same as in Example I) l6 Mineral Spirits (Same as in Example 56 Aluminum Powder (Same as in Example 12 Asbestos 'fiifii '(s'ri' iiiifiblfifff: III: III 17 Total 100 Any suitable method may be employed for thoroughly mixing the ingredients to produce a more or less homogeneous mass. A suitable method of preparation is first to pour a mixture of the bituminous material and the resin in heated molten condition into a suitable heated container, adding the volatile solvent while stirring until a homogeneous mass obtains, cooling to about room temperature after the solvent is thoroughly mixed with the binder, adding the filler while stirring until a uniform mixture is obtained, and finally incorporating the aluminum powder or paste while stirring until all evidence of lumps disappears.

It is possible with the composition of this invention to provide a material which does not have the requisite amount of solvent when packaged,

with instructions that it be thinned before use with a specified amount of desired thinner.

However, the paint is preferably employed as a ready-mixed or ready-to-use compositionthat may be applied directly as a coating, without further mixing, other than the usual mere stirring. The coating formed can be made of the thickness described in the previously mentioned patent. The paint is particularly adapted for application to asphaltic prepared roofing and asphaltic shingles, but it is also useful for the painting of galvanized iron roofing and siding, and for the painting of electric wire and cable. It may be applied either by brush, or. by spraying because of its relatively low viscosity.

We claim:

1. A solvent thinned metallic ornamental paint consisting essentially of the following in parts by weight:

Binder of bituminous material selected from the group consisting of asphalt, coal tar pitches and stearine pitches and coumarone-indene resin in the proportions of about 25% to 75% by weight of bituminous material to about 75% to about 25% by weight of the resin, respectively 12 to 17 Volatile solvent for the binder comprising a coal tar solvent to 50 Aluminum powder 8 to 12 Filler, the major proportion of which is asbestos fiber 10 to 21 2. A solvent thinned metallic ornamental paint consisting essentially of the following in parts by weight:

3. A solvent thinned metallic ornamental paint consisting essentially of the following in parts by weight:

70 to 50 8 to 12 Binder of about 50% by weight of coumarone-indene resin and about 50% by weight of asphalt 12 to 17 Volatile solvent for the binder comprising at least 20% by weight of a coal tar solvent Aluminum powder Filler, the major proportion of which is asbestos fiber '10 to 21 "4. A solvent thinned metallic ornamentaLpaint con'sisting essentially of the following in parts 5. A solvent thinned metallic-ornamental paint consisting essentially of thefollowing in parts by weight:

As ihalt 9 "Coumarone-in'dene resin "6 Mineral 'spirits 4 "Coal tarnaptha' solvent 16 filum'inum powder 12 Asbestos "-fiber "17 .6. -A solventthinned-metallic ornamental paint ;consisting essentially of a binder of bituminous material selected from the group consisting "of asphalt, coal tar 'pitches and stearine pitches,

and cOumarone-indene resin, in proportions of about 25% to 75% by weight of the bituminous material 'to about 75% to about 25% by weight of the-resin; volatile solvent for'the binder aluminum powder; anda filler, the majorproportion of which is asbestos fiber; the total quantity of:binder:-and -the solvent constitutingabout 67% =tolabout-82%" of the total weight .of the-paint; :the

total quantity of the filler "and @the aluminum owder constituting about 18% :to:about;33% the wtotalweight of lthe paint; the solvent to binder :ratio being about 3 to '6 parts by weight iofithe solvent to about 1 part by weighttof the binder; the filler to aluminum powder ratio being about 0.8 to 2.5 :partsbyweight of 'theifillerito'iabout 1 p'art by weight of thelpowder; the binder to a1uminum powder ra'tio being about 1 to 2 parts by weight of the -binderto about 'l partby weig'ht-of the aluminum powder; and the binder to the filleriratio beingabout 0.55 t0 1.'7 parts 'by weight o'f the binder'to about 1 part by weight of the filler. FREDERICK =A. S'TOLZ. EDLEY J. VAUGHIJR.

REFERENCES \CITED The following references are of :record in 'the file of this-patent:

'IJNITED "STATES PA'TEN'I'S Number Name Date 1,292,907 sperr-et-al .a Jan. 28, 1919 1,849g86'7 .Eckert fMar. :15, 1932 2,188,204 Marc et a1. Jan. 23, .1940 2,477,236 Buchanan July 26, "I949 OTHER REFER'ENCES Asphalts arid Allied Substances by Abraham, 4th edition, page 5511, and Table 24 following page 370. 

6. A SOLVENT THINED METALLIC ORNAMENTAL PAINT CONSISTING ESSENTIALLY OF A BINDER OF BITUMINOUS MATERIAL SELECTED FROM THE GROUP CONSISTING OF ASPHALT, COAL TAR PITCHES AND STEARINE PITCHES, AND COUMARONE-INDENE RESIN, IN PROPORTIONS OF ABOUT 25% TO 75% BY WEIGHT OF THE BITUMINOUS MATERIAL TO ABOUT 75% TO ABOUT 25% BY WEIGHT OF THE RESIN; VOLATILE SOLVENT FOR THE BINDER; ALUMINUM POWDER; AND A FILLER, THE MAJOR PROPORTION OF WHICH IS ASBESTOS FIBER; THE TOTAL QUANTITY OF BINDER AND THE SOLVENT CONSITUTING ABOUT 67% TO ABOUT 82% OF THE TOTAL WEIGHT OF THE PAINT; THE TOTAL QUANTITY OF THE FILLER AND THE ALUMINUM POWDER CONSTITUTING ABOUT 18% TO ABOUT 33% THE TOTAL WEIGHT OF THE PAINT; THE SOLVENT TO BINDER RATIO BEING ABOUT 3 TO 6 PARTS BY WEIGHT OF THE SOLVENT TO ABOUT 1 PART BY WEIGHT OF THE BINDER; THE FILLER TO ALUMINUM POWDER RATIO BEING ABOUT 0.8 TO 2.5 PARTS BY WEIGHT OF THE FILLER TO ABOUT 1 PART BY WEIGHT OF THE POWDER; THE BINDER TO ALUMINUM POWDER RATIO BEING ABOUT 1 TO 2 PARTS BY WEIGHT OF THE BINDER TO ABOUT 1 PART BY WEIGHT OF THE ALUMINUM POWDER; AND THE BINDER TO THE FILLER RATIO BEING ABOUT 0.55 TO 1.7 PARTS BY WEIGHT OF THE BINDER TO ABOUT 1 PART BY WEIGHT OF THE FILLER. 